When CBS has the 2nd football game, I've been adding 30 minutes at the end of The Mentalist, which is currently set up as a season pass.

My expected behavior would be for 30 minutes to be added on to that particular episode of The Mentalist (that I've added pad to)

The outcome I'm getting is that The Mentalist records at it's normal time (not adding the 30 minutes), and then adds a secondary recording that is an hour and a half long. It isn't labelled as The Mentalist either.

Is this just the way it is, or is there some kind of user error?

What I would like to happen is that I get The Mentalist, with 30 mins of pad, not an extra recording on top of it.

I changed my season pass for the Mentalist to add an hour onto the end. It starts recording at 9:30 (seems to be the scheduled time lately) and records for two hours, the hour that is in the schedule and one more hour on the same recording. Haven't missed any Mentalist yet. I have no idea how you're getting a separate recording. That is not the behavior I get.

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This bug has been discussed in other threads as well. I assume the OP is making the changes to recording padding on Sunday night. The bug appears to be triggered when you makes changes to the recording padding within a few hours of the actual recording start time.

Making the change to the season pass itself should remove the double recording bug if/until Tivo corrects the issue in the software.

It's not just padding, it's any change to an existing scheduled recording. I changed Covert Affairs from a season pass recording to a one time recording (via iPad) and it messes up the ToDo list entry.